Find a rectangular equation for the plane curve defined by the parametric equations.

x = sin(theta)
y = 3cos(theta)

1 answer

we know sinØ = y/r and cosØ = x/r
and tanØ = y/x

then for the given:
sinØ = x = y/r
rx = y ---> r = y/x

3cosØ = y = 3x/r
ry = 3x
(y/x)y = 3x
y^2 = 3x^2
y = ±√3 x